Multiple contact ignition interrupter assembly

ABSTRACT

AN IGNITION INTERRUPTER ADAPTED TO CAUSE A SUCCESSION OF A PAIR OF SPARKS FOR EACH GAS CHARGE IN EACH CYLINDER OF AN INTERNAL COMBUSTION ENGINE, INCLUDES AN ARM PIVOTALLY MOUNTED ON A MOUNTING PLATE, A STATIONARY CONTACT MOUNTED ON THE PLATE AT THE FRONT SIDE OF THE ARM, A FIRST MOVABLE CONTACT MOUNTED ON THE FRONT SIDE OF THE ARM OPPOSITE THE STATIONARY CONTACT, A SECOND MOVABLE CONTACT MOUNTED ON THE REAR SIDE OF THE ARM AND ELECTRICALLY CONNECTED TO THE FIRST MOVABLE CONTACT, A THIRD MOVABLE CONTACT POSITIONED OPPOSITE THE SECOND MOVABLE CONTACT TO THE REAR OF THE ARM AND SLIDABLY MOUNTED WITHIN A HOUSING FIXED TO THE MOUNTING PLATE, THE THIRD MOVABLE CONTACT BEING ELECTRICALLY CONNECTED TO THE STATIONARY CONTACT, A CAM ROTATABLY MOUNTED ON THE PLATE, AND A FINGER MOUNTED ON THE FRONT SIDE OF THE ARM FOR FOLLOWING THE CAM TO CAUSE THE ARM TO PIVOT RECIPROCATIVELY FORWARDLY AND REARWARDLY SO THAT THE STATIONARY CONTACT AND THE FIRST CONTACT ARE CAUSED TO ENGAGE ELECTRICALLY TO CAUSE THE PRODUCTION OF A FIRST SPARK DURING A FORWARD MOTION OF THE ARM AND THE SECOND AND THIRD CONTACTS ARE CAUSED TO ENGAGE ELECTRICALLY TO CAUSE THE PRODUCTION OF A SUBSEQUENT SPARK DURING A REARWARD MOVEMENT OF THE ARM. A FIRST SPRING FIXED TO THE MOUNTING PLATE URGES RESILIENTLY THE FINGER FORWARDLY INTO ENGAGEMENT WITH THE CAM, AND A SECOND SPRING MOUNTED WITHIN THE HOUSING URGES RESILIENTLY THE THIRD MOVABLE CONTACT FORWARDLY INTO A FORWARD POSITION TO ABUT THE SECOND CONTACT DURING THE REARWARD MOTION OF THE ARM, THE CAM BEING ARRANGED TO CONTINUE TO DRIVE THE ARM AGAINST THE FORCE OF THE SECOND SPRING AFTER THE SECOND CONTACT ENGAGES THE THIRD CONTACT.

United States Patent [191 Janci 1 1 MULTIPLE CONTACT IGNITIONINTERRUPTER ASSEMBLY [76] Inventor: John Janci, 1125 N. Karlov Ave,

Chicago, Ill. 60651 [22] Filed: Dec. 13, I972 [2]] Appl. No.: 316,262

Primary E.raminer.l. R. Scott Attorney, Agent, or Firm-John C. Brezinaet a1.

[57 1 ABSTRACT An ignition interrupter adapted to cause a succession ofa pair of sparks for each gas charge in each cylinder of an internalcombustion engine, includes an arm pivotaJly mounted on a mountingplate, a stationary cont- [11] 3,819,884 1 1 :June25, 1974 act mountedon the plate at the front side of the arm, a first movable contactmounted on the front side of the arm opposite the stationary contact, asecond movable contact mounted on the rear side of the arm andelectrically connected to the first movable contact, a third movablecontact positioned opposite the second movable contact to the rear ofthe arm and slidably mounted within a housing fixed to the mountingplate, the third movable contact being electrically connected to thestationary contact, a cam rotatably mounted on the plate, and a fingermounted on the front side of the arm for following the cam to cause thearm to pivot reciprocatively forwardly and rearwardly so that thestationary contact and the first contact are caused to engageelectrically to cause the production of a first spark during a forwardmotion of the arm and the second and third contacts are caused to engageelectrically to cause the production of a subsequent spark during arearward movement of the arm. A first spring fixed to the mounting plateurges resiliently the finger forwardly into engagement with the cam, anda second spring mounted within the housing urges resiliently the thirdmovable contact forwardly into a-forward position to abut the secondcontact during the rearward motion of the arm, the cam being arranged tocontinue to drive the arm against the force of the second spring afterthe second contact engages the third contact.

4 Claims, 2 Drawing Figures ASSEMBLY The present invention relates to anignition interrupter, and it more particularly relates to an interrupterfor ignition systems to cause a plurality of sparks to be supplied toeach gas charge in each cylinger of an internal combustion engine.

Ignition interrupters having multiple sets of contact points have beenprovided for causing a plurality of sparks to be supplied to thecylinders of an internal combustion engine. Several types of suchmechanisms have been employed, but they have been unnecessarily andunduly complex in nature. For example, reference may be made to US. Pat.Nos. 2,674,663; 2,685,622; 2,713,096; 2,854,534; 2,94l,049 and3,319,0l8. In each of the foregoing patents, there is disclosed anignition interrupter which includes a plurality of sets of contactpoints and a plurality of arms for actuating the contact points. Forexample, in US. Pat. No. 2,674,663 there is disclosed a pair ofspaced-apart stationary contacts, and a pair of pivotally movable armseach having a movable point mounted thereon for moving alternately intoengagement with the two corresponding stationary contacts under thecontrol of a cam and a cam follower. The cam is a polygonal cam, and inorder for the pair of contacts which close when the cam followerapproaches the point of the cam, the arm carrying the movable contact ofsuch pair of contacts is made flexible so that as the camfollowerapproaches the point of the cam, the flexible arm bends so as not todamage the contacts as the follower continues to move toward a point ofthe cam. A device is provided for connecting the two arms together sothat they can readily move toward one another during the bending of theflexible arm, but they are restrained from moving apart when theflexible arm moves in the reverse direction as the cam follower movespast the point of the cam. Therefore, it would be highly desirable tohave an ignition interrupter which is efficient in operation andsimplified in construction.

Therefore, the principal object of the present invention is to provide anew and improved ignition interrupter, which causes a plurality ofsparks to be supplied to each combustible mixture in each enginecylinder, and which is efficicnt in operation and simplified inconstruction.

Briefly, the above and further objects are realized in accordance withthe present invention by providing an ignition interrupter having asingle arm pivotally mounted on a mounting plate, a stationary contactmounted on the plate at the front side of the arm, a first movablecontact mounted on the front side of the arm opposite the stationarycontact, a second movable contact mounted on the rear side of the armand electrically connected to the first movable contact, a third movablecontact positioned opposite the second movable contact to the rear ofthe arm and electrically connected to the stationary contact, a slidemounted within a housing fixed to the plate for mounting slidably thethird movable contact on the mounting plate, a cam rotatably mounted onthe plate for moving a finger mounted on the front side of the cam tocause the arm to pivot reciprocatively forwardly and rearwardly so thatthe stationary contact and the first contact are caused to engageelectrically during a forward motion of the arm and the second and thirdcontacts are caused to engage electrically during a rearward motion ofthe arm. A first spring mounted on the mounting plate urges resilientlythe finger forwardly into engagementwith the cam, and a second springurges resiliently the third movable contact forwardly into a forwardposition to abut the second contact during the rearward motion of thearm, the cam being arranged to continue to drive the arm against theface of the second spring after the second contact engages the thirdcontact. As a result, only a single arm is provided in accordance withthe present invention, and a mechanism is provided to adjust the tensionon the second spring to thereby facilitate adjustment of the interruptermechanism.

The invention, both as to its organization and method of operation,together with further objects and advantages thereof, will best beunderstood by reference to the following detailed description taken inconnection with the accompanying sheet of drawings, wherein:

FIG. 1 is a front elevational view of the ignition interrupterconstructed in accordance with the present invention, showing thecontact arm in a first position; and

FIG. 2 is a front elevational view of the interrupter similar to FIG. 1,but showing the arm in a second position.

Referring now to the drawings, and more particularly to FIG. 1 thereof,there is shown an ignition interrupter 10, which is constructed inaccordance with the present invention, and which is adapted to controlan ignition system to supply a pair of sparks sequentially to eachgasoline-air mixture charge in each cylinder of an internal combustionengine (not shown). The interrupter generally comprises an arm 12pivotally mounted at 14 to a mounting plate 16 and has a finger or camfollower 18 which is pressed into engagement with an octagonal cam 20which in turn is rotatably driven by the cam shaft 22 of the engine. Aleaf spring 24 urges the arm 12 and thus the finger 18 into engagementwith the cam 20, and the distal end portion of the arm I2 carries a pairof movable contacts 24 and 26 on opposite sides thereof to cooperatewith a pair of spaced-apart contacts 28 and 31.

For the purpose of enabling the contact 31 to be movable relative to theplate 16 to permit the arm 12 to continue to pivot rearwardly after thecontacts 26 and 31 engage one another as shown in FIG. I, a coil spring33 mounted within a housing 35 fixed to and electrically connected tothe mounting plate 16 resiliently urges forwardly a rodlike slider 37having the movable contact 31 fixed to its outer end. As a result, asthe arm 12 pivots rearwardly after the contacts 26 and 31 engage, thecam 20 continues to drive the arm 12 rearwardly and the spring 33compresses to permit the arm to continue its rearward motion. After thearm 12 reverses its motion under the control of the cam 20 and commencesits forward motion, the spring 33 expands to cause the contacts 31 and26 to remain in engagcment with one another until an enlarged internalend portion or head 37A engages an annular shoulder 38 of the housing35. Thereafter, the contacts 26 and 31 move apart.

Considering now the interrupter 10 in greater detail with reference tothe drawings, the ignition interrupter 10 of the present invention isdisposed in a distributor 39 having a circular support plate 40 on whichis secured the mounting plate 16 fixed thereto by two screws 42 and 44extending through respective elongated slots 46 and 48 and threaded intoengagement with threaded holes (not shown) in the support plate 40. Themounting plate 16 is adjustably mounted on the support plate 40 topermit adjustment of the position of the contacts by permitting theplate 16 to be adjusted positionally relative to the support plate 40,whereby such an adjustment varies the timing of the closing of thecontacts. An upstanding car 51 of the grounded mounting plate 16supports and is electrically connected to a stud 53, which is fixed tothe stationary contact 28. It should be understood that the movablecontact 26 connect via the housing 35 to the plate 16 and the contact 28are both connected electrically to the grounded plate 16. An upstandingcar 55 of the plate 16 carries an insulated bushing 57 extending throughan opening in the car 55 and supports'a bolt 59 extending therethroughto serve as a terminal post for a terminal 60 of a cable 62 electricallyconnected to the coil (not shown) of the ignition system, the terminal60 having a hole (not shown) therein for receiving the bolt 59 between anut 63 threaded onto the bolt 59 against the bushing 57 and a nut 64threaded onto the bolt 59 against the terminal 60. The end portion ofthe spring 24 is apertured to fit over and receive the bolt 59 betweenthe nut 63 and the bushing 57 to connect electrically the arm 12 to theterminal 60 and to mechanically secure the spring 24 to the plate 16.The arm 12 is insulated by an insulating washer (not shown) from theplate 16, and the opposite end of the spring 24 is connectedmechanically and electrically to the arm 12, the cam being composed ofinsulating material so that the arm 12 and its movable contacts 24 and26 are electrically connected via the spring 24 to the terminal 60 andare insulated from the grounded plate 16.

An upstanding car 66 is apertured to receive and support the housing 35which includes an externally threaded tubular member 68 extendingthrough the opening in the car 66 and held in place by a pair of nuts 71and 73 threaded onto the tubular member 68 on opposite sides of the car66 and tightened thereagainst. The enlarged internal end 37A of theslider 37 has a boss 77 for seating the end portion of the spring 33 andis adapted to engage the internal shoulder 79 of the tubular member 68to limit the extent of the outward movement ofthe slider 37, the annularshoulder 79 surrounding an opening in the end of the tubular member 68.At the opposite end of the tubular member 68 a plug 82 has an externallythreaded shank portion 84 threaded into the internal threaded interiorchamber or compartment of the tube-like member 68 for adjusting thetension of the spring 33, thereby adjusting the spacing between thecontacts 31 and 26. An enlarged external head 86 of the plug 82 isslotted to facilitate the adjustment thereof. It should be understoodthat gross adjustments of the housing 35 may be made by adjusting itsposition relative to the ear 66 by in turn adjusting the nuts 71 and 73,and a fine adjustment may be made by the plug 82.

As the cam 20 rotates in a counter-clockwise direction, the arm 12 isfirst moved to a position where the finger 18 is near a low surface onthe cam 18 and the contacts 24 and 28 engage as shown in F IG. 1 tocause subsequently a first spark to be generated by the ignition systemfor igniting a gas charge in a cylinder. The first spark is generatedwhen the contacts 24 and 28 separate. Thereafter, the finger l8 followsthe cam toward a point thereon. and in so doing, as shown in FlG.- 2,the arm 20 pivots backwardly and the contacts 26 and 31 engage to causethe generation of a second spark subsequently thereto for the samecylinder to insure proper and complete combustion of the gas chargecontained therein. The finger 18 continues to move along the cam to thenext point thereon and then past the point toward the next low surface,and in so doing the arm 12 is driven backwardly against the force of thespring 33 and then moves forwardly under the force of the spring 24while the spring 33 maintains the contacts 26 and 31 in interengagementuntil the end portion 37A abuts the shoulder 38. The second spark isgenerated when the contacts 26 and 31 separate. 1n the preferredembodiment, the cam and the other parts of the interrupter are arrangedsuch that the second spark follows the first one by a time interval,which includes a coil build-up time interval sufficient to permit afield to be established in the coil of the ignition system for causingsubsequently the second spark. The build-up time of the coilfor thesecond spark is determined by the length of time between the make andthe break of the contact points 26 and 31.

While the present invention has been described in connection with aparticular embodiment thereof, it will be understood that many changesand modifications of this invention may be made by those skilled in theart without departing from the true spirit and scope thereof.Accordingly, the appended claims are intended to cover all such changesand modifications as fall within the true spirit and scope of thepresent invention.

What is claimed is:

1. An interrupter for an ignition system, comprising:

a mounting plate;

an arm pivotally mounted on said plate;

a stationary contact mounted on said plate at the front side of saidarm;

a first movable contact mounted on the front side of said arm oppositesaid stationary contact;

a second movable contact mounted on the rear side of said arm andelectrically connected to said first movable contact;

a third movable contact positioned opposite said second movable contactto the rear of said arm and electrically connected to said stationarycontact;

mounting means for connecting slidably said third movable contact tosaid mounting plate;

cam means rotatably mounted on said plate;

a finger mounted on the front side of said arm for following said cam tocause said arm to pivot reciprocatively frontwardly and rearwardly sothat said stationary contact and said first contact are caused to engageelectrically during a forward motion of said arm and said second andthird contacts are caused to engage electrically during a rearwardmotion of said arm;

first spring means mounted on said mounting plate for urging resilientlysaid finger forwardly into engagement with said cam; and

second spring means for urging resiliently said third movable contactforwardly into a forward position to abut said second contact duringsaid rearward motion of said arm, said cam being arranged to continue todrive said arm against the force of said second spring means after saidsecond contact engages said first contact.

mounting means further includes a retaining plug extending within theback end of said chamber for retaining said second spring means therein,said plug being adjustably positioned within said chamber to adjust thetension on said second spring means.

4. An interrupter according to claim 3, wherein said plug is externallythreaded and said chamber is internally threaded to receive threadablysaid plug for adjustment purposes.

